1. Field of the Invention
The present invention relates to a recovery device and an ink jet recording apparatus provided with the recovery device, and more particularly to a recovery device disposed at a different location and an ink jet recording apparatus provided with the recovery device.
2. Related Background Art
Recording apparatuses which have features of printer, copying machine and facsimile, or are employed as the output device for composite equipment or workstation containing a computer, a word processor and so on, are configured to record the image (including characters or symbols) onto the recording sheet (recording medium) such as a paper or a plastic thin plate (e.g., OHP), based on image information. Such recording apparatuses can be classified into an ink jet system, a wire dot system, a thermal system, a thermal transfer system and a laser beam system, depending on the recording method for recording means used.
In a serial type recording apparatus which takes the recording system of scanning in a direction crosswise to the conveying direction of recording sheet (sub-scan direction), the image can be recorded on a desired range of the recording sheet in the manner, after setting the recording sheet at a predetermined recording position, to repetitively perform the operation of recording the image (including characters or symbols) by recording means (recording head) mounted on a carriage moving (scanning) along the recording sheet, the operation including recording one line, then feeding (sub-scanning) the sheet by a predetermined amount, and recording (scanning) the image at the next line. On the other hand, in a line type recording apparatus which performs the recording only by the sub-scanning of feeding the recording sheet in a conveying direction, the image is recorded over the recording sheet in the manner, after setting the recording sheet at a predetermined recording position, to consecutively perform the operation including recording one line at a time and feeding the sheet by a predetermined amount (pitch feeding).
Among them, an ink jet system (ink jet recording apparatus) which performs the recording by discharging the ink from recording means (recording head) onto the recording sheet has the advantages in which recording means can be made compact, the higher definition image can be recorded at higher speed, the ordinary paper is usable for recording without needs of any special treatment, the running cost is lower, there is less noise owing to the non-impact method, and the color image is readily recorded by using color inks. In particular, a line-type recording apparatus which uses recording means of the line type of having an arrangement of a number of discharge ports in a direction of the sheet width allows for the high speed recording.
Specifically, recording means (recording head) of the ink jet system of discharging the ink by the use of heat energy can be easily fabricated with an arrangement of liquid paths (discharge ports) at high density by forming electricity-heat converters, electrodes, liquid path walls, and a ceiling plate as the film on a substrate through a semiconductor fabrication process including etching, vapor deposition and sputtering, and thus can be made more compact. Also, by utilizing the merits of the IC technology or micro process technology, recording means can be easily constructed in longer size and planer form (two-dimensional form), and readily afforded a full-multi configuration or higher density packaging. On the other hand, there are a variety of demands for the material of recording sheet, and in recent years, in addition to the papers or resin thin films which are ordinary recording sheets, the use of thin papers or proposed papers (punched papers for filing or scored papers, or other papers of any shape) has been demanded.
In the ink jet recording apparatus, if the foreign matter such as paper powder or contaminant is stuck to the ink discharge portion of recording means (recording head), or the ink on the discharge port portion is dried, thickened and fixed therearound, the discharge ports may be clogged, resulting in a discharge failure (including undischarge). Thus, in order to prevent the clogging, the ink discharge portion is sealably closed with a cap when not in use, and a recovery device is utilized for recovering the ink discharge by sucking the ink from the discharge ports via the cap by suction means such as a pump. Note that in the serial type ink jet recording apparatus, the enclosing operation (capping operation) with the cap can be achieved in such a way as to move the recording head to a capping position provided outside the recording area, and place the cap into contact with the ink discharge portion located at the capping position.
Also, in the ink jet recording apparatus, cleaning means is provided for removing the foreign matter sticking to the ink discharge portion (discharge port face) of the recording head. An example of the cleaning means is a mechanism for cleaning (wiping) the discharge port face of the recording head with a pliable wiper (wiping member).
However, in the conventional cleaning means for the recording head, several technical problems have been posed as follows. Firstly, the recovery device including cleaning means has generally a complex constitution and many parts, thereby increasing the cost and making the apparatus larger. Secondly, because of the disposition of the wiper (wiping member) between the recording area and cap means, recording head may touch with the wiper every time of the capping operation or predischarge operation into the cap, for which a latch means to extend or retract the wiper is provided to avoid rubbing against the recording head face more than necessary, resulting in more complex constitution and causing greater noise. Note that a constitution for changing the contact force against the recording head without extending or retracting the wiper has been proposed, but it is undeniable that there is a risk that the flaw may occur on the recording head face. Thirdly, the use of a dedicated drive source for the contact and release between the cap and the recording head will give rise to a significant cost increase. Fourthly, when the capping operation is performed using the movement of carriage, the load on a carriage motor may be increased, thus requiring the carriage motor a size larger to be used, whereby there is much room for improvement in the respects of optimization and efficiency of the carriage motor. Further, fifthly, because the ink may be dispersed in separating the wiper away from the head after cleaning, it is necessary to secure a wider spacing between the recording area and the wiper to yield a dead space, which results in the larger apparatus. For example, there is a recovery mechanism as shown in FIG. 13 which makes effective use of this space. This has a recess portion 166 for receiving the ink for predischarge between the recording area and the wiper 185. And the cap 165 is more separated away from the recording area than the wiper 185 is. Therefore, the recovery device will require a space as wide as the length of L.sub.1.